Walter Smith fears the Rangers fans' previous offences in Europe could lead to a ban. Photograph: Bogdan Cristel/Reuters

The Rangers manager, Walter Smith, has admitted he fears the club could be banned from competing in Europe because of the latest misdemeanours of their supporters.

Trouble flared at half-time during Rangers' Champions League draw with Unirea Urziceni in Romania on Wednesday night and the Scottish club will be hauled before Uefa next Thursday. Fines already issued since 2006 because of the conduct of the Rangers support in Europe mean a more severe penalty is possible this time around; the manager has contemplated the impact of a ban.

"Obviously we have received warnings before and it will be hugely disappointing if it does impact on the footballing side of things," Smith said. "I'm not currently aware of the whole background of the situation. So whether you're critical of the supporters or critical of the policing and the stewards ... it is left up to you.

"But it is a situation Rangers have been in before and we can't run away from the fact. If it does impact and the consequences mean we do have to miss European games then that would be an enormous blow for the club. I have no indication as to what Uefa are proposing but the thing Rangers can't run away from is it's not an isolated incident."

Pressed further on the impact any European ban would have on Rangers, who are facing financial troubles at present, Smith added: "In the current climate it's the last thing the club needs. European football is important to this club."

Uefa, meanwhile, has begun disciplinary proceedings against Unirea over a "lack of organisation" regarding the entry procedure for spectators.